Vibration damping line suspension apparatus



ug 20, 1968 s. N. scHLElN l 3,397,857

VIBRATION DAMPING LINE SUSPENSION APPARATUS Filed July 11, 1966 3Sheets-Sheet 1 INVENTOR SEYMOUR N. SCHL EIN fida/Mya@ /KH' Affamey Aug-20, 1968 s. N. scHLElN 3,397,857

VIBRATION DAMPING LINE SUSPENSION APPARATUS Filed July 11, 1966 5Sheets-Sheet 2 /NVENTO/'P SEYMOUR N. SCHLE//V Alforney s. N. SCHLEIN3,397,857

VIBRATION DAMPING LINE SUSPENSION APPARATUS 5 Sheets-Sheet 3 Aug. 20,1968 Filed July 1l, 1966 2/4 23/ 'lEf f/f Attorney United States PatentO I 3,397,857 VIBRATION DAMPING LINE SUSPENSION APPARATUS Seymour N.Schlein, University Heights, Ohio, .aisslgnor to The FannerManufacturing Company, 'a Dlvlson of Textron Inc., Cleveland, Ohio, acorporation of Rhode Island Continuation-impart of application Ser. No.345,225, Feb. 17, 1964. This application July 11, 1966, Ser. No. 564,139The portion of the term of the patent subsequent to July 12, 1983, hasbeen disclalmed 26 Claims. (Cl. 248-63) This is a `continuation-in-partof application Ser. No. 345,225, filed Feb. 17, 1964, now Patent No.3,260,487 entitled, Line Suspension. This invention relates .to1mprovements in line suspension ldevices and more particularly tosuspension devices for suspending lines from the cross arm of a pole ortower which device will damp vibrations or oscillations of the line.

The above noted patent application discloses a line suspension systemutilizing a hanger and a pair of preformed helically wound armor rodswhich are attached to the line by wrapping the ends of the armor rodsaround the lines and securing the central portions thereof to thehanger. The line thus secured by the armor rods is free of stressinducing clamping devices, and with such a system the line is supportedin such a manner that there are no bending strains placed on it due tocontact with the saddle or clamps. An additional advantage of such asystern over the prior art clamps is that there is a large mar*- gin ofsafety because one or more of the parts may fail and the other partsstill retain their holding power to prevent the line from falling,during which time the partial failure of the parts may be detected andthe part replaced before a complete failure occurs.

The present invention constitutes an improved line suspension devicewhich Will provide all the advantages of the system of said applicationand in addition will provide excellent damping of vibrations andoscillations occurring in the line due to the Aeolian effect. To reduceand dampen these vibrations, the line support of this invention utilizesseveral effective vibration damping systems.

Still other advantages of the invention, and the invention itself, willbecome more apparent from the following description of severalembodiments thereof which are illustrated in the accompanying drawingsan-d form a part of this speciiication.

-In the drawings:

FIG. 1 is a side elevational view of one embodiment of a line suspensiondevice according to this invention suspending a line therefrom;

FIG. la is an elevational view of a line engaging element;

FIG. 2 is a sectional view of the device of FIG. 1 showing the line andline engaging elements in section;

FIG. 3 is a sectional view taken substantially along the planedesignated by the line III-III of FIG. l;

FIG. 4 is a side elevational view of a device similar to FIG. l incorporating inertia type damping devices;

FIG. 5 is an end elevational view of the device of FIG. 4;

FIG. 6 is a plan view of a device similar to FIG. 3, showing theincorporation of inertia type `damping devices;

FIG. 7 is an end elevational View of the device of FIG. 6;

FIG. 7a is a detail view of another type of mounting of an inertia typedamper;

FIG. 8 is a fragmentary view of another embodiment of the eye structureof a hanger;

3,397,857 Patented Aug. 20, 1968 ICC FIG. 9 is a fragmentary view ofanother embodiment of the mounting of the arms;

FIG. 10 is a side elevational view of another embodiment of a dampingdevice of this invention;

FIG. l1 is a sectional view taken substantially along the planedesignated by the line XI-XI of FIG. 10;

FIG. l2 is a sectional view taken substantially along the planedesignated by the line XII-XII of FIG. 11;

FIG. 13 is a sectional view similar to FIG. 1l, of still anotherembodiment of a damping device according to this invention;

FIG. 14 is a sectional view taken substantially along the planedesignated by the line XIV-XIV of FIG. 13;

FIG. 15 is a sectional view of still another embodiment of a dampingdevice according to this invention; and

FIG. 16 is a side elevational view of the device of FIG. 15.

Briefly, according to the present invention an improved line suspensiondevice is provided which has pivotally mounted support members or arms.The arms are each provided with means which are positioned to engage andhold the center portion of a line engaging element. The line engagingelements each include helically Wound armor rods usually with a hardtwist central section. The arms are free to move pivotally in a verticalplane and preferably the arms have friction surfaces for the dissipationof energy as heat. The invention also contemplates inertia type damperssecured to the arms, and also torsion means to improve the dampingproperties of the device.

More specilically, and referring now to the drawings, and moreparticularly to FIGS. l through 3, one embodiment of an improved linesuspension device according to this invention is shown. The device isshown being used in its typical environment attached to a clevis 10 atthe bottom of a string of insulators 12.

The line suspension device includes a hanger member 14 having an eye 16at its upper end which is pivotally secured to the clevis 10 by a bolt18 and nut 19. A pair of support arms or members 20 are provided whichare secured to the hanger member 14 by a bolt 22 which passes throughboth of the arms 20 and through the hanger 14. A nut 24 is threaded onthe end of the bolt and can be tightened against the arms 20 to anydegree of tightness. The arms 20 are thus pivotally mounted to thehanger 14 and are free to move pivotally in a vertical plane. The innersurfaces of each of the arms 20 frictionally engage the outer surfacesof the hanger 14. Each of the arms 20 is provided with a pair oflongitudinally extending spaced flanges 28 which dene therebetweengrooves 30.

The hanger member 14 is provided with a slot defining a longitudinallyextending line receiving passage 32 curving upwardly from the center ofthe hanger to both ends. The groove 32. bisects the hanger member andprovides a pair of downwardly extending legs 34, the lower ends of whichare provided with eyes 36. A sheave 38 is provided which can bedetachably secured in eyes 36.

The line attaching means or engaging element, in the preferred form isshown in FIG. la, and includes a plurality of armor rods assembled andhelically wound into partial lay end portions 40, with a -hard twistedcenter portion 42. The description of the formation of this, as well asother line attaching means which also may be used in the presentinvention, is discussed fully in said Patent No. 3,260,487. It is to beunderstood that these attaching means may take various other forms andthe element of FIG. la and the others described in said application aremerely illustrative of the type of elements that can be used with thisinvention. For example, engaging elements having partial end portionswith straight or untwisted central portions could be used.

To utilize the device, the hard twisted zone of one element is laid inthe groove of one arm 20 and the flanges 28 are bent over to firmly gripand secure the midportion 42 thereof. The hard twisted zone 42 ofanother element is lplaced in the groove 30 of the other arm 20 and theflanges are bent over in the same way. The line L is then raised intoposition into the passage 32 between the legs 34, the sheave 38 is theninserted, and the helical ends of each of the wire gripping elements arewrapped around the wire on opposite sides of the hanger member as shownin FIG. 1. If each of the ends 40 are initially a half-lay, the twotogether will form a full-lay around the line on both sides of thehanger as shown. However, the two ends 40` may be less than half-lay inwhich case the two together will be less than a full-lay. In some casesthis may be desirable to increase the holding power of the elements.-The sheave 38 supports the line L in place while the line is beingsecured by the wire gripping elements and it may either be left in thedevice permanently to provide a rest for the line after assembly iscompleted or it may be removed, allowing the line to hang free. Ineither case the support of the line is provided by the wire grippingelements and no clamping devices are secured to the line to cause anincrease in stresses, and the line is maintained in the groove 32 freeof clamping stresses at its apex. The nut and bolt 22. and 24 are thentightened sufciently to provide the desired amount of frictionalresistance between the surfaces of the arms 20 and the outer surfaces ofthe hanger 14. The amount of frictional resistance will depend upon theamount of damping desired due to this frictional action, as will bedescribed presently.

The damping action of the device shown in FIGS. 1 through 3 will occurby two specific mechanisms. The first of these mechanisms is a phaseinterference which results from the pivotal mounting of the arms 20 withrespect to the hanger 14. The oscillations in the line L on oppositesides of the device will almost invariably be out-of-phase with eachother. These oscillations are transmitted from the line to the supportelements which are connected to the arms 20. Since the arms 20 arepivotally mounted they will tend to move responsive to the oscillationsof the line and the out-of-phase oscillations will each .tend to canceleach other out to the extent that lthey are out-of-phase with eachother. Hence the damping is proportional to the phase difference, and ifoscillations on opposite sides of the hanger were precisely 180out-of-phase and of the same amplitude they would absolutely cancel eachother at the pivot arms.

The second mechanism of damping the oscillations is that of energyabsorption by the frictional engagement of surfaces of the arms withsurfaces of the hanger, and the outer surfaces of the hanger around i-tseye being in frictional sliding engagement with the surfaces of theclevis. The frictional engagement of these surfaces physically resiststhe occurring oscillations in the line, absorbing the energy, anddissipating it as heat. The amount of energy absorbed is dependent uponthe force of friction to be overcome which, in turn, is dependent uponthe size of the surfaces, the character of the surfaces and thetightness of the nut and bolt 22 and 24 and the tightness of the boltand nut 18 and 19. Therefore, it is preferable to provide goodfrictional characteristics to the engaging surfaces of the arms andhanger and the hanger and clevis so that the maximum utilization of thisfrictional force absorption of energy can be made. Friction increasingfacings such as are used for clutches or the like may be employed toincrease friction and thereby increases the effective damping of thedevice. Likewise it may be desirable to snugly tighten the nut and bolt22 and 2.4 and bolt and nut 18 and 19 so as to provide a maximum useable:amount of frictional force. However, the nut and bolt should not betightened so tight as to bind the arms 20 to the hanger member 14, orthe hanger to the clevis thus preventing any movement and defeating theeffect of the frictional movement of these two members. The tightness ofthe nut and bolt can quickly be determined by observing the line andhanger .1-4 and testing the action of the line in moving the .arms 20and the hanger 1-4 during installation. If the adjustment proves to bewrong, or the bolts loosen, adjustments can be made periodically tomaintain the proper amount of frictional force.

Thus, when a line is supported utilizing a device of this invention, allof the benefits derived from the device described in Patent No.3,260,487 are obtained and, in addition, an improved damping ofoscillations is achieved without sacrificing any of the benefitsderived.

In order to achieve even further damping, inertia type damping devicescan be secured to the arms 20, as shown in FIGS. 4 through 7. In FIGS. 4and 5 a device similar to that of FIG. l is shown having a pair ofinertia type dampers secured to each of the arms 20. Each of the inertiatype dampers includes a stiff cable 46 having at the end thereof aweight 48. The cables 46 are secured to the arms 20 in any convenientmanner such as by placing them in apertures 50, as shown in FIG. 4, andsecuring them by means of a set screw 52. In the embodiment of FIGS. 6and 7, the inertia type dampers each take the form of a single weighthaving a pair of cables, each of the cables being connected to one endof the arms on opposite sides of the hanger member 14 with the cables ofthe other weight being connected to the -other ends of the arms 20, alsoon opposite sides of the hanger 14.

FIG. 7a shows a different type of mounting of the damper wherein thecable is secured to an externally threaded collar 53 which is screwedinto the arm 20.

The weights as shown are solid cylinders, but hollow cylinders can alsobe employed. Also corona reducing shapes such as spheres can be used.

With the devices as shown in FIGS. 4 through 7, an additional dampingaction is provided by the inertia type dampers. This type of damping iswell known in the art and these dampers used in conjunction with the twodamping mechanisms of this device previously described provides anoutstanding damping device, which will damp both large and smalloscillations and provide an outstanding device for line support.

Additional damping can be achieved by torsion means which absorb energyand dissipate it as heat. Two such embodiments are shown in FIGS. 8 and9. In FIG. 8 the eye 16 is provided with a tube of resilient material54, such as rubber. A sleeve 56 passes through the rubber 54 and has apolygonal central bore 56. A bolt with a mating polygonal shank passesthrough the bore 56 and engages the clevis which also has a matingpolygonal bore. This provides a torsion effect to damp oscillations.

Similarly, in FIG. 9 the openings in the arms 20 through which the bolt22 passes are provided with a rubber or other resilient tube 60 having acentral sleeve 62 with a polygonal bore 64. A bolt having a matingpolygonal shank passes through the polygonal bore 64 and a similarlyshaped polygonal bore in hanger 14. This will provide for a torsiondamping of oscillations as the arms 20 move with respect to the hanger14.

Referring now to FIGS. 10, 11, and 12, another embodiment of the dampingdevice of this invention is shown. In this embodiment the hanger member114 is similar to that of the device of FIGS. 1 through 3, but the armsare modified and take the form of longitudinally split blocks. Theopposite sections of these blocks 121 and 123 are provided with grooves125 and 127 which form a through central bore when the sections of theblocks 121 and 123 are fitted together. In order to position the blocksexactly to align the grooves and 127, a tongue and notch construction129 is provided for locating the blocks. A bolt 122 extends through bothof the arms 120 and through the hanger member 114 and has threaded onthe end thereof a nut 124 which will adjust the frictional resistance ofthe arms against the hanger 114, as in embodiment of FIG. 1. A bearing122a is provided in each of the arms surrounding the bolt 122 to reducewear thereon during operation of the device. Although these bearings aredesirable, they are not essential.

This embodiment is readily adapted to be assembled completely in thefield. To assemble the device, each of the sections 121 and 123 of thearms 120 are interlocked around the central porti-on 42 of a supportelement and the arms are then secured to the hanger member 114 by thenut and bolt 122 and 124. The ends of the support element are thenwrapped around the line in the same manner as previously described. Inthis embodiment also the arms may be provided with inertia type dampersfor additional damping action and a support sheave may also beincorporated. Also torsion type damping may be incorporated.

Referring now to FIGS. 13 and 14, still another embodiment of thisinvention is shown. In this embodiment the hanger member 214 is providedwith a pair of longitudinally extending channels 231 on opposite side ofand parallel to line receiving passage 232. The channels 231 curveupwardly from their centers to their opposite ends similar to thecurvature of the passage 232. Support members or arms 220, similar tothose shown in the embodiment of FIGS. through 12, are disposed in thechannels 231 and each is secured therein by a bolt 233 passing throughbearings 222a, in the arms 220, and into the central portion of thehanger member 214. In this embodiment each of the support members 220has two surfaces in contact with the surface of the hanger member 214,thus doubling the frictional resistance for any given level of torque ofthe bolts 233. This will increase the frictional damping withoutincreasing the torque on the bolts. Also, in this embodiment thefrictional resistance of each of the support arms 220 can be adjustedseparately since each is secured by a separate bolt. However, it is tobe understood that a single bolt could be used, passing through bothsupport arms 220 and completely through the hanger member 114 andsecured with a nut similar to the previously described ernbodiments,thereby permitting a single adjustment of the frictional resistance,resulting from the torque of the bolt. It is also to be understood thatin the previously described embodiments, separate bolts could be used tosecure each arm to the hanger member in a manner similar to that ofFIGS. 13 and 14, so that in those embodiments the frictional resistanceof each arm could be adjusted separately. Also, in the embodiment ofFIGS. 10 through 14 inertia type 4damping devices similar to those ofFIGS. 4 through 7a, could also be connected to the arms to provideadditional inertia damping, and torsion type damping sleeves could alsobe provided.

Referring now to FIGS. l5 and 16, still another em bodiment of thisinvention is shown wherein no hanger is utilized. A pair of supportmembers 320 are mounted directly on the clevis for pivotal movement bybolt and nut (not shown). The bolt passes through eyes 316 at the top ofthe support members and through the clevis (not shown). The supportmembers 320 are each provided with upper engaging friction surfaces 320aand lower spaced surfaces 320b. The lower spaced surfaces 320b definetherebetween a line receiving groove of the shape previously described.Each of the support members 320 has a longitudinally extending groove325 which together with a mating groove 327 formed in cover plate 320Cdefines a bore for receiving the central portion of the wire grippingelements. The cover plates 320e` are bolted to their respective supportmember by a pair of bolts 322 passing through the cover plates andthreaded into the support member 320. In this embodiment the supportmembers are free to pivot independently directly on the clevis mounting.

As can be seen in FIG. 16, the line engaging bores defined by thegrooves 325 and 327 curve downwardly in the vertical plane toward theopposite ends from the centers of the support members. Thisconfiguration may be desirable in some cases to reduce stress on theline engaging elements where the elements enter the support arms. Thisstress is due to curvature of the elements caused by their own weightand the weight of the supported line. This is particularly beneficial inthis embodiment since a sheave cannot be allowed to remain between thesupport arms because of their relative motion; however, this curvedconfiguration can be used in any of the other embodiments.

It is to be understood that in this embodiment inertia type damperscould be utilized as previously described and also the previouslydescribed resilient mounting at the clevis could be incorporated.

Although several embodiments of this invention have been shown, it isbelieved that the invention essentially comprises a device for themounting of a line which will maintain the line free of damping stressesat its apex, and will engage the line with arm members pivoted to absorbthe energy of oscillation in the line. The energy absorption takes placethrough various combinations of phase cancellation, dissipation as heatthrough torsion means, and as work in inertia type dampers. Thesevarious modes can be combined in such a way in the device to giveexcellent oscillation damping without the detrimental effects ofclamping the wire at its apex.

Having thus described my invention in several embodiments thereof, I amaware that numerous and extensive departures may be made therefromwithout departing from the spirit or scope of the invention as definedby the appended claims.

I claim:

1. A line suspension device comprising, a pair of support members, eachof said support members being split block means together defining acentral bore, means to suspend said support members from a support andpivotally mount them for pivotal movement in a vertical plane, each ofsaid support members holding a line engaging element, each of said lineengaging elements including at least one flexible extension portionextending from said support member and a gripped portion disposed withinsaid central bore, said extension portions including means to engage aline.

2. The device of claim 1 wherein said support members are mounted on acentral hanger member.

3. The device of claim 2 further characterized by means for pivotallymounting said support members on said central hanger member.

4. The device of claim 3 wherein said means for providing a pivotalmounting of the support members on said hanger member includes boltmeans passing through both said hanger member and said support members.

5. The device of claim 3 wherein said means for pivotally mounting saidsupport members includes bearing means carried by said support members.

6. A line suspension device comprising, a pair of support members, meansto suspend said support members from a support and pivotally mount themfor pivotal movement in a vertical plane, said support members includingmutually engaging surfaces to dissipate energy as heat, each of saidsupport members including gripping means holding a line engagingelement, each of said elements including at least one flexible extensionportion extending therefrom, each of said flexible extension portionsincluding means to engage a line.

7. The device of claim 6 wherein said support members include meansdefining a line receiving groove therebetween.

8. The device of claim 6 wherein said gripping means holding the lineengaging elements includes means for detachably securing said grippingelements.

9. The device of claim 8 wherein said means to detachably secure saidelements includes cover plate means having a through central opening inwhich said gripping elements reside.

10. A line suspension device comprising, a hanger member, said hangermember having a slot extending upwardly from the bottom thereof defininga line receiving passage of sufcient height and width to accommodate theline to be supported and maintain the line free of clamping forces atits apex, a pair of channels disposed on Aopposite sides of said linereceiving passage, and line support members being disposed in each ofsaid channels, said support members including gripping means holding aline engaging element, each of said elements including at least oneflexible extension portion extending therefrom, each of said flexibleextension portions including means to engage a line.

11. The device of claim 10 wherein said support members include splitblock means.

12. The device of claim 10 wherein each of said support members ismounted on separate pivot means in its respective channel.

13. The device of claim 10 wherein said means for pivotally mountingsaid support members includes bearing means carried by said supportmembers.

14. A line suspension device comprising, a pair of support members,means to suspend said support members from a support and pivotally mountthem for pivotal movement in a vertical plane, each of said supportmembers including gripping means holding a line engaging element, eachof said elements including at least one flexible extension portionextending therefrom, each of said flexible extension portions includingmeans to engage a line.

15. The device of claim 14, wherein said means holding the line-engagingelements includes grooves to seat said line-engaging elements and meansdisposed to at least partially close the grooves when the line-engagingelements are seated therein.

16. The device of claim 14, wherein said means to suspend and mount saidsupport members includes a hanger member, and said support members arepivotally mounted on said hanger member.

17. The device of claim 16, further characterized by said hanger memberand said support members having frictionally engaging surfaces todissipate energy as heat.

18. The device of claim 16, wherein said hanger member is provided witha slot extending upwardly from the bottom defining a line receivingpassage of sufficient height and width to accommodate the line beingsupported and maintain the line free of clamping forces at its apex.

19. The device of claim 16, wherein bolt means mount said supportmembers.

20. The combination of claim 19, wherein separate bolts mount eachsupport member.

21. The combination of claim 19, wherein a single bolt mounts each ofsaid support members. i

22. The device of claim 14, further characterized by at least oneinertia type vibration damper carried by at least one of said supportmembers.

23. The device of claim 22, further characterized by a plurality ofinertia type dampers symmetrically arranged.

24. The device of claim 14, further characterized by torsion meansdisposed to absorb oscillating energy as torsional movement.

25. The device of claim 16, wherein torsion means are interposed betweenthe support member and hanger member.

26. The device of claim 22, wherein torsion means are disposed to absorboscillating energy between the hanger member and the support mounting.

References Cited UNITED STATES PATENTS 3,260,487 7/ 1966 Schlein 248-63471,096 3/1892 Briggs 248-63 X 1,065,866 6/1913 Fraley 248-63 X2,086,150 7/1937 Austin 248-63 2,149,875 3/1939 Talbott 248-63 2,731,5091/1956 Becker 174-42 2,783,297 2/ 1957 Badeau 248-63 3,113,173 12/1963Horovitz 174-40 3,163,706 12/1964 Peterson 174-42 3,219,298 11/ 1965Ruhlman 248-63 3,260,487 7/ 1966 Schlen 248-63 FOREIGN PATENTS 488,92012/1952 Canada.

ROY D. FRAZIER, Primary Examiner.

R. P. SEITTER, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,397,857 August 20, 1968 Seymour N'. Schlein It is certified that errorappears in the above identified patent andthat said Letters Patent arehereby corrected as shovm below z Column 5, line 16, "side" should readsides Column 6, llne I4, "damping" should read clamping Signed andsealed this 10th day of February 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, IR.

Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer

1. A LINE SUSPENSION DEVICE COMPRISING, A PAIR OF SUPPORT MEMBERS, EACHOF SAID SUPPORT MEMBERS BEING SPLIT BLOCK MEANS TOGETHER DEFINING ACENTRAL BORE, MEANS TO SUSPEND SAID SUPPORT MEMBERS FROM A SUPPORT ANDPIVOTALLY MOUNT THEM FOR PIVOTAL MOVEMENT IN A VERTICAL PLANE, EACH OFSAID SUPPORT MEMBERS HOLDING A LINE EN-